PDA

View Full Version : ICSP Pins



Gord11
- 7th December 2011, 11:15
Hello,,,

Can anyone tell me what happens to the ICSP pins during programming?

If i have a PIC with dedicated ICSP pins, nothing at all on them just the ICSP connections, how
should i leave the pins in the program, ie. should they be set low? if so would this have any impact on the programmer i
f it was then connected again later.

I surpose what i am actually asking is what does the EPIC USB programmer do with the pins
so i know how to leave them in normal use.

I hope this makes sense............

Gordon.

mackrackit
- 7th December 2011, 11:33
Any pin that is not used/connected during runtime should be made an output. You can look at the ICSP pins as being not used/connected.

Gord11
- 7th December 2011, 12:38
Thanks for the reply..

So would it matter if the pin was set high or low, when the programmer was connected?


Gordon

mackrackit
- 7th December 2011, 13:53
I have never used the Epic so I do not know how it is made so go with low to be safe.

J. Mark Wolf
- 8th December 2011, 13:22
Not entirely sure what your asking but thought I would comment:

The MCLR pin on some PIC devices have a max voltage of 9 volts, 16F1527 for instance, but some device programmers can generate voltages as high as 13.5Volts on this pin. This means you should add a series resistor and clamping zener diode on the MCLR pin for such devices.

As far as configuring the ICSP pins in your code, I've always just configured them as inputs, and relied on the hardware programming algorythm built into each device to handle all the details during the programming cycle.

Get's more complicated if you use the ICSP pins for functions other than dedicated programming pins.